A national sex offender registry came into existence Wednesday, but past offenders who have already finished serving sentences won't be listed on it unless they commit new crimes.

The $2-million project has been in the works since February 2002. That's when the federal government gave in to years of lobbying and agreed to establish a registry that would require sex offenders being released from jail to let police know their whereabouts.




They will be charged if they don't do so, or if they fail to update the information if they move.

Those convicted of serious sex crimes might have to continue updating police about where they're living for the rest of their lives.

The law creating the registry received royal assent on April 1 of this year.

Ontario already has a similar registry for sex offenders released within its borders, but has no jurisdiction to monitor people if they move to another province.

In Alberta, information about some high-risk offenders appears on a government website that any member of the public can read.

Police database will contain detailed information

The national registry starts out empty. Offenders will be added as court officials from the provinces determine who should be on the list from among the population of prisoners being released or finishing conditional sentences in the community.

The information will be available to police forces nationwide through the Canadian Police Information Centre database, and will include fingerprints and physical descriptions, as well as photographs in some cases.

In cases where they feel the community is at risk from a certain person, individual police forces can decide to issue a public warning.

Some skepticism over registry's effectiveness

Police and victims of sexual assault have long been calling for such a registry, but some critics are already questioning how effective it will be.

To stave off constitutional challenges, Ottawa decided to allow offenders to challenge their inclusion on the registry.

Ontario's three-year-old list of more than 6,000 offenders is now being challenged through the courts because it is a mandatory one, with no appeal avenues for people who object to letting police know where they are.

As well, the rules for including someone on the list could vary across the country.

Justice officials within each province will decide which offences are sexual in nature, and come up with a system to let the thousands of convicted sex offenders now in the prison system know about their obligation to register.

Judges will hear challenges and could decide to take people off the list based on different criteria established in each province.

Finally, the federal government decided not to include people who have finished serving their sentences because of fears the law could be challenged on privacy grounds.

Still, Ottawa expects the registry to include several thousand names within a year.